Molding, compression molding and punching are conventionally known as methods for processing an elastomer such as rubber. In particular, when performing fine processing on the surface of a rubber, a predetermined pattern is formed by molding or compression molding. However, related to the conventional method, because a rubber base material includes flexibility and has no shape-retaining property, the more the pattern becomes fine, it may not be possible to maintain the pattern shape when peeled from a mold, the microstructure becomes torn and processing of a rubber structure having a fine structure was practically impossible.
For example, a method of forming a nanoscale pattern is described in Japanese Laid Open Patent 2007-237360 in which a piece to be processed using a material that is elastically deformable is elastically deformed in an orthogonal direction of the processing surface, an uneven pattern is formed by lithography or the like, and the piece to be processed is returned to a normal state before elastic deformation. However, the aspect ratio of the pattern shown in Japanese Laid Open Patent 2007-237360 is at most 1, and the manufactured structure by photolithography is troublesome which is not practical.